THERMODYNAMIC AND CONFORMATIONAL PROPERTIES OF STYRENE-METHYL METHACRYLATE BLOCK COPOLYMERS IN DILUTE SOLUTION .I. PREPARATION AND CHARACTERIZATION

An anionic polymerization procedure for preparing styrene and methyl methacrylate block copolymers is described. The products were characterized by combustion analysis, osmometry, light scattering measurement, and gel permeation chromatography. The analyses showed that the block copolymers consisted of linear three-block chains except for a few cases. The correlation between the heterogeneities of molecular weights and of composition as described by light scattering apparent molecular weights in different solvents is discussed. The heterogeneities can be described by two parameters for the polydispersities of precursor polystyrene and poly(methyl methacrylate) subchains and by the average composition of the block copolymer. Preliminary data on the light scattering conformational analyses are given. The results suggest that the block copolymer chains would assume the conformations similar to any flexible linear homopolymers at least in the solvents, toluene and butanone, examined in this study. © 1969.